route/route: support FIB lookups using rtnl

Using the flnl_* family of functions to perform FIB lookups is rather
limited. In particular, there seems to be no way of resolving the
nexthop. By hooking into RTM_GETROUTE, a regular rtnl route object is
returned instead.

1 files changed, 27 insertions, 0 deletions

diff --git a/lib/route/route.c b/lib/route/route.c
index 509099a..a761549 100644
--- a/lib/route/route.c
+++ b/lib/route/route.c
@@ -124,6 +124,33 @@ int rtnl_route_build_add_request(struct rtnl_route *tmpl, int flags,
 			       result);
 }
 
+int rtnl_route_lookup(struct nl_sock *sk, struct nl_addr *dst,
+		      struct rtnl_route **result)
+{
+	struct nl_msg *msg;
+	struct rtnl_route *tmpl;
+	struct nl_object *obj;
+	int err;
+
+	tmpl = rtnl_route_alloc();
+	rtnl_route_set_dst(tmpl, dst);
+	err = build_route_msg(tmpl, RTM_GETROUTE, 0, &msg);
+	rtnl_route_put(tmpl);
+	if (err < 0)
+		return err;
+
+	err = nl_send_auto(sk, msg);
+	nlmsg_free(msg);
+	if (err < 0)
+		return err;
+
+	if ((err = nl_pickup(sk, route_msg_parser, &obj)) < 0)
+		return err;
+
+	*result = (struct rtnl_route *)obj;
+	return wait_for_ack(sk);
+}
+
 int rtnl_route_add(struct nl_sock *sk, struct rtnl_route *route, int flags)
 {
 	struct nl_msg *msg;